Merge abotchkov@bk-internal.mysql.com:/home/bk/mysql-5.0-opt

into  mysql.com:/home/hf/work/mrg/mysql-5.0-opt


sql/sql_select.cc:
  Auto merged

sql/sql_select.cc

@@ -7621,7 +7621,8 @@ static COND* substitute_for_best_equal_field(COND *cond,
           break;
       }
     }
-    if (!((Item_cond*)cond)->argument_list()->elements)
+    if (cond->type() == Item::COND_ITEM &&
+        !((Item_cond*)cond)->argument_list()->elements)
       cond= new Item_int((int32)cond->val_bool());
 
   }